1. Field of the Invention
The present invention relates to a method and an apparatus of manufacturing a one-way clutch which has sprags, a ribbon spring, an inner retainer, and an outer retainer and for which an idling state and a torque transmitting state can be set in accordance with the rotational directions of an outer ring and an inner ring, and more particularly to a technique of automating the manufacture of one-way clutches.
2. Description of the Related Art
Conventionally, in the operation of assembling a one-way clutch 20 as shown in FIGS. 19A and 19B and having sprags 21, a ribbon spring 22, an outer retainer 23, and an inner retainer 24, most of the operation depends on the manual operation.
Namely, to assemble the one-way clutch 20, a predetermined number of sprags 21 are consecutively inserted and fitted into sprag inserting windows 28 provided in the ribbon spring 22 at predetermined intervals in the longitudinal direction, as shown in FIG. 20.
Next, as shown in FIG. 21, the sprags 21 are adjusted from the inner side of the outer retainer 23 to sprag inserting windows 30 provided in the outer retainer 23 at predetermined intervals along the circumferential direction of the outer retainer 23. Then, outer ring-side end portions 25 of the sprags 21 are consecutively inserted and fitted into the sprag inserting windows 30 of the outer retainer 23 in such a manner as to twist the ribbon spring 22 into which the sprags 21 have been inserted and fitted.
Further, the sprags 21 are adjusted from the outer side of the inner retainer 24 shown in FIGS. 19A and 19B to sprag inserting windows 31 provided in the inner retainer 24 at predetermined intervals along the circumferential direction of the inner retainer 24. Then, inner ring-side end portions 26 of the sprags 21 are consecutively inserted and fitted into the sprag inserting windows 31 of the inner retainer 24. These inserting operations are manually performed.
In the above-described related method, there has been a problem in that expert skill is particularly required in the operation shown in FIG. 21 in which the outer ring-side end portions 25 of the sprags 21 are inserted and fitted into the sprag inserting windows 30 of the outer retainer 23.
Namely, when the outer ring-side end portions 25 of the sprags 21 are inserted and fitted into the sprag inserting windows 30 of the outer retainer 23, it has been necessary to perform the operation by adjusting the sprags 21 from the inner side of the outer retainer 23 to the sprag inserting windows 30 of the outer retainer 23 and in such a manner as to twist the ribbon spring 22 by using of the flexibility of the ribbon spring 22. At this time, if an undue force is inadvertently applied to the ribbon spring 22, it leads to the breakage of the ribbon spring 22. Accordingly, it has been difficult to automate the operation of assembling the one-way clutches 20 through mechanization.